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Toy example using opencv 3.0 object in a custom class

asked 2016-04-19 11:54:36 -0500

mcExchange gravatar image

updated 2016-04-19 12:10:29 -0500

I'm new to opencv 3.0. I cannot figure out how to use a SVM object in a custom class. Can someone give me a toy example how to do it?

Here is an example for opencv 2.4.x:

// Class Definition    
class myClass{
    public:
        myClass();

    private:
        CvSVM svm;
};

// Constructor
myClass::myClass()
{
    myClass::svm.load("Some/hard/coded/path/to/a/SVM/File");
}

I guess the class definition should look similar to this:

class myClass {
    private:
    static cv::Ptr<cv::ml::SVM> svm;
};

But my Constructor keeps on failing:

myClass::myClass(){
    myClass::svm->load("Some/hard/coded/path/to/a/SVM/File");
}

with the following error message:

error: no matching function for call to 'cv::ml::SVM::load(const char [120])'
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answered 2016-04-19 12:14:06 -0500

berak gravatar image

updated 2016-04-19 12:16:21 -0500

for opencv3, try like this:

(Algorithm::load is a static template function nowadays, it returns a new instance)

// Class Definition    
class myClass{
    public:
        myClass();

    int predict(const Mat &query) const;

    private:
        Ptr<ml::SVM> svm;
};

// Constructor
myClass::myClass()
{
    svm = Algorithm::load<ml::SVM>load("Some/hard/coded/path/to/a/SVM/File");
}

int myClass::predict(const Mat &query) const
{
    return (int)svm->predict(query);
}
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Comments

1

sidenote: 3.0 has a couple of warts wrt. machine-learning. you probably should update to current master (3.1, atm.)

berak gravatar imageberak ( 2016-04-19 12:19:32 -0500 )edit

I'm not sure entirely whether it's 3.0 or 3.1 I'm dealing with, since I'm doing surgery in the code of somebody else, but it's clearly not 2.4.x.

mcExchange gravatar imagemcExchange ( 2016-04-19 12:24:24 -0500 )edit

cerr << cv::getBuildInformation(); will help you to find out.

berak gravatar imageberak ( 2016-04-19 12:30:16 -0500 )edit

I guess it's kind of fine thanks! I still get some error while compiling, but that might be due to some missing linked library: error: undefined reference to 'cv::ml::SVM::create()'

mcExchange gravatar imagemcExchange ( 2016-04-19 13:24:05 -0500 )edit
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Asked: 2016-04-19 11:54:36 -0500

Seen: 281 times

Last updated: Apr 19 '16